| US 7,600,976 B2 | ||
| Rotor blade twist distribution for a high speed rotary-wing aircraft | ||
| Ashish Bagai, Hamden, Conn. (US); and Lauren Kreuscher, New Haven, Conn. (US) | ||
| Assigned to Sikorsky Aircraft Corporation, Stratford, Conn. (US) | ||
| Filed on Aug. 23, 2006, as Appl. No. 11/508,414. | ||
| Application 11/508414 is a continuation in part of application No. 11/140706, filed on May 31, 2005, granted, now 7,252,479. | ||
| Prior Publication US 2007/0110582 A1, May 17, 2007 | ||
| Int. Cl. B64C 27/46 (2006.01) | ||
| U.S. Cl. 416—223R [416/238; 416/DIG. 2; 416/DIG. 5] | 25 Claims |
| 1. A main rotor blade assembly for a rotary wing aircraft comprising:
a main rotor blade root region containing a root region twist within said main rotor blade root region transverse to a feathering
axis, said root region twist having a positive twist gradient;
a main rotor blade inboard region outboard of said main rotor blade root region, said main rotor blade inboard region containing
an inboard chord within said main rotor blade inboard region transverse to said feathering axis;
a main rotor blade main region outboard of said main rotor blade inboard region, said main rotor blade main region containing
a main region twist within said main rotor blade main region transverse to said feathering axis, said main region twist having
a negative twist gradient;
a main rotor blade tip region outboard of said main region, said tip, region containing a tip region twist within said main
rotor blade tip region transverse to said feathering axis, said tip region twist having a negative twist gradient more negative
than said main region twist gradient; and
a blade chord defined between a leading edge and a trailing edge, said trailing edge defined along a root trailing edge of
said main rotor blade root region, an inboard region trailing edge of said main rotor blade inboard region, a main region
trailing edge of said main rotor blade main region and a tip region trailing edge of said main rotor blade tip region, said
inboard region trailing edge defining a point A and a point B, said point B outboard of said point A, said main region trailing
edge defining a point C and a point D, said point D outboard of said point C, said blade chord increasing between said point
A and said point B and decreasing between said point C and said point D, said main rotor blade maximum chord located between
said point B and said point C from said root attachment section to said main region section and decreasing from said main
region section to said tip region section.
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